the two bios that i´ve read and found very insightful are :
ich,romy:tagebuch eines lebens edited by renate seydel
you cannot call it a real "biography" ,not even an autobiography .it´s a collection of written testimonies by romy beginning with her diary which she wrote during her time at boarding school at the age of 12-14,then her first film experiences and later continues with notices she wrote for friends,lovers,colleagues,photographers etc. these are romy´s own words and they give a deep and sometimes painful insight into her feelings and experiences.
the second:romy schneider by alice schwarzer (a famous german feminist).she met romy several times druing the latter half of the 70-s,and had long conversations with her.she definitely came closer to the woman beyond the filmstar romy schneider.very welll written too.you should have no problems to find it at amazon.de or you could also try abebooks.de or.com.
if you´re also interested in picture books you might also enjoy
romy schneider-ein leben in bilder by renate seydel.the pictures are also accompanied by a lot information,so there`s also alot to read
romy schneider-das private album by isabelle giordano -contains a lot of pics that were never published before but solely from the period in which she was married to daniel biasini her second husband:the text is interesting too since the author interviewed biasini and their daughter sarah and also colleagues like the director claude sautet.the image that sarah and daniel biasini create is sometimes quite different from what you read elsewhere
romy-c´est la vie by giancarlo botti :this photographer has created some wonderful pictures of romy during 1961 and 1980.the book has been out of print for quite a while but you could probably find it at amazon_marketplace;abebooks,or ebay
here some scans from the books i`ve mentioned
these are all from romy_c`est la vie....i`m falling asleep in front of my pc so i`d better stop now and continue another time